Raven Politics: Understanding and Use of Social Relationships
funded by FWF: START (2008-1013), project leader: Prof. Dr. Thomas Bugnyar

Social life has been suggested as one of the main driving forces for the development of higher cognitive abilities in non-human, and human, primates. Yet there are open questions concerning the mechanisms underlying ‘intelligent’ behaviour and the socio-ecological conditions that promote investment in cognitive skills. Recently, the idea of the bird family Corvidae representing a mirror group to the primates in respect to cognitive capacities has gained momentum. Understanding the social life of corvids may thus be critical in our attempt to understand primate cognition, since comparison between these groups may offer the unique opportunity to identify which cognitive abilities are common to social living irrespective of phylogeny and how selection has acted to produce these solutions. The intend in this proposal is therefore to investigate social complexity as driving force for brain evolution in corvids and to provide a comprehensive study on the use of social knowledge in an avian model system, the common raven Corvus corax.

Ravens show striking abilities in judging and manipulating competitors but also engage in referential communication, social learning, and various forms of cooperation on the basis of social relationships. This makes them promising candidates to examine their ‘political’ skills from a Machiavellian and a Vygotskian point of view. Hence, this proposal aims at testing what ravens know about other individuals and their social relations and how they make use of their knowledge in daily life. Studies shall follow two parallel lines of research, building blocks (i) on individual recognition and understanding of dyadic and triadic relations and (ii) on the formation, regulation, and use of valuable relations under fission-fusion dynamics. Furthermore, studies shall feature a combination of laboratory and field work by utilizing our unique captive colony of hand-raised adult birds, their yearly offspring that will be observed first in captivity and then in the field, and habituated wild birds. Finally, studies shall be conducted in collaboration with leading experts in primatology, experimental psychology and behavioural biology, enabling me to utilize a variety of methods (e.g. operant procedures, playbacks, matched-controlled observations, hormonal correlates) on one model system and to selectively conduct comparative studies with closely related species to address effects of phylogeny and ecology. The integrative aspect of the proposed project shall open new possibilities in the research on avian cognition and is expected to have both an impact on current hypotheses on mental evolution and a strong outreach component to lay persons. If birds with a radically different neurobiology and evolutionary trajectory to that of primates come to understand, and use, their social world in a similar way to primates, this would provide strong support for the idea of a convergent evolution and help us understand the selection pressures that may have boosted the evolution of sophisticated mental skills in non-human, and human, primates.

Affiliate relations and cooperation in ravens, Corvus corax
part of the European research network "COCOR (Cooperation in Corvids)"
funded by ESF-EUROCORES framework TECT (2007-2010), principal investigator: Prof. Dr. Thomas Bugnyar

Observational evidence suggests that corvid flocks represent individualized societies with members selectively exchanging low- and high-risks behaviours such as preening and coalition formation. Moreover, recent studies emphasize a crucial role of affiliate relationships that may form between siblings but also between non-related individuals. What is not yet clear is to what extent individuals make tactical use of their relations in cooperative interactions. The aim of the project is to 1) test if ravens’ affiliate relationships work as alliances in conflicts, leading to a system of dependent ranks both within and between sexes, 2) determine if, and how, individuals maintain affiliate relations when their partners are experimentally prevented from retaliating social support and 3) examine the birds’ willingness to share resources with ‘reliable’ and ‘unreliable’ partners.

Cooperation and economic behaviour in corvids
part of the European research network INCORE (Integrating Cooperation Research across Europe)
funded by EU, FP6-NEST (2007-2010), principal investigator: Prof. Dr. Thomas Bugnyar

Corvids have been suggested to show complex cognitive abilities similar to those of primates in the context of similar socio-ecological problems. One of the most fascinating aspects of their social life is the tactical and economical use of cooperative behaviour. Corvids are known to facultatively engage in helping at the nest (e.g. carrion crows), active recruitment of non-relatives to food sources (e.g. ravens), food sharing (e.g. jackdaws), coalitionary support between and within sexes (e.g. ravens, rooks), and post-conflict consolation (e.g. ravens, rooks). Taken together, results indicate a high flexibility in the birds’ decision of whether or not to cooperate in certain situations, some knowledge about potential cooperation partners and the use of tools both in the social and technical domain.

So far, issues related to corvid-cooperation have been investigated as isolated topics, focusing either on specific proximate or functional aspects. Extending the view of different programs, coordinating ongoing studies and adjusting already-used procedures pose technical and practical challenges and call for improved networking between the established labs in Austria (KL Research Station, Univ. Vienna), France (Univ. Strasbourg), Great Britain (Univ. Cambridge, Univ. Oxford), Spain (Univ. Valladolid) and Italy (Univ. Trieste). This work package is aimed to improve the exchange of information between the European corvid labs in order to coordinate their activities and integrate their ongoing work on cooperative behaviour into the broad framework of other European programs (GEBACO, TECT).

Reasoning in birds
funded by: FWF (P20538-B17), project leaders: Prof. Dr. Kurt Kotrschal (Dept. Behavioural Biology) & Dr. Christian Schloegl

Corvids and parrots possess advanced cognitive abilities. Both groups possess similar sized brains, with those areas enlarged which are supposed to be important for advanced cognitive abilities ("cognitive cerebrotype"; Iwaniuk & Hurd 2005). Corvids and parrots possess prolonged juvenile periods, form complex fission-fusion societies and are extremly long-living. In the corvids, the competition over food caches has been suggested to be the driving force for the evolution of their advanced cognitive abilities. Parrots, in contrast, do not cache food and do not compete with conspecifics over food sources regularly. In the past, most cognitive research on birds focused on the cognitive domains each species had been suspected to be specialised in, i.e. ravens had been tested in caching-related tasks, New Caledonian crows in tasks related to tool-use, etc. Comparative research, however, has been neglected mainly.

With this project, we will our expand our research to various corvid and parrot species, to gain an comparative overview of the cognitive abilities of the different species. Within this project, reasoning, i.e. the ability to infer missing information by deduction from available information, will be of particular interest.


Fairness and inequity avoidance in carrion crows (Corvus corone corone)
funded by „For Women in Science“ L’Oreal Austria, ÖAW and BMWF; Project leader: Dr. Claudia Wascher

Different forms of cooperative behaviours can be observed in human as well as non-human animal societies (e.g. cooperative breeding, cooperative hunting, alliance formation). What makes these cooperative behaviours so attractive for scientific research is the element of instability. Why should individuals invest without a guarantee of net returns? In the proposed study I plan to investigate a specific aspect of cooperation namely the sensitivity towards unequal reward or effort distribution. For a long time, inequity avoidance has been thought to be a uniquely human feature, until it has been shown in primate species and recently, also in dogs. Until the present day all studies focused on mammalian species. I plan to investigate sensitivity to unequal reward structure for the first time in a bird species, the carrion crow (Corvus corone corone). Tests will be conducted on a group of 8 captive carrion crows at the Konrad-Lorenz Forschungstelle (KLF) in Upper Austria. In the last two years these birds were trained to exchange a token (non-edible item) for food with a human experimenter. This procedure has been applied in primate species to answer questions like, how individuals deal with delay of reward (Dufour et al. 2007), differences in food quality (Drapier et al. 2005) or unequal reward (Brosnan & De Waal 2003; Brosnan et al. 2005). To my knowledge, the crows at the KLF are the first bird species capable to perform in exchange tasks. I plan to replicate tests conducted in primates on inequity avoidance starting in November 2009. For comparative reasons, I will follow the methods used by Brosnan and co-workers (2003; 2005): A focal subject and a model individual will be tested together in 4 experimental conditions: (1.) equity test: both subjects will receive a low-value food reward for exchanging; (2.) inequity test: the test subject witnesses the model individual exchanging for a high value reward, afterwards the focal subject itself, receives a low-value reward for the exchange; (3.) effort control: the focal subject watches the model individual receiving high quality reward without exchanging, then the focal subject has to exchange for the reward; (4.) food control test: the high-value reward is presented but not given to the model, afterwards the focal subject has to exchange for the reward. For each individual and in each condition I will measure the frequency of refusals to exchange and the latency to exchange. In a final step, starting in April 2010, I will investigate how social relationships affect inequity aversion. It has been previously shown in chimpanzees that tolerance for inequity increases with social closeness (Brosnan et al. 2005). I will test all individuals in the inequity test once with an affiliated and once with a non-affiliated social partner. To be sensitive for other individuals efforts and payoffs compared to the own ones is thought to be a crucial cognitive skill for cooperation but until now has only be shown in mammalian species. I expect carrion crows, to be sensitive to inequity and to respond with refusal to exchange when being unequally gratificated. If they are also sensitive to the effort an individual is investing, they should also respond with refusal in the effort control condition, when another individual receives gratification without the effort of exchanging whereas the focal individual has to exchange to receive the reward. Additionally, I also expect the identity of the model individual to influence the tolerance to inequity. When tested with affiliated individuals focal subjects should refuse less frequent compared to being tested with non-affiliated individuals. The objective of the proposed study is to examine a form of fairness (inequity aversion) in a bird species. In a broader sense, however, my goal is to initiate a research program to investigate carrion crows cooperative skills, aiming at a better understanding of the evolution of cooperative behaviour and its cognitive underpinnings.

Publications

Recent papers

Bugnyar, T., Stöwe, M. & Heinrich, B. 2004. Ravens, Corvus corax, follow gaze direction of humans around obstacles. Proceedings Royal Society London Series B 271 , 1331-1336.

Bugnyar, T. & Kotrschal K. 2004. Leading a conspecific away from food in ravens, Corvus corax. Animal Cognition 7 , 69-76.

Bugnyar, T. & Kotrschal, K. 2002. Observational learning and the raiding of food caches in ravens, Corvus corax : Is it “tactical deception”? Animal Behaviour 64 , 185-195.

Bugnyar, T. & Kotrschal K. 2002. Scrounging tactics in free-ranging ravens. Ethology 108 , 993-1009.

Kijne, M. & Kotrschal, K. 2002: Neophobia affects choice of food item size in group-foraging common ravens (Corvux corax). Acta ethologica 5, 13-18.

Bugnyar, T., Kijne, M. & Kotrschal, K. 2001. Food calling in ravens: are yells referential signals? Animal Behaviour 61 , 949-958.

Bugnyar, T. & Kotrschal, K. 2001. Movement coordination and signalling in ravens (Corvus corax): an experimental field study. Acta Ethologica 3 , 101-109.

Kotrschal, K., Bugnyar, T. & Stöwe, M. 2001. Kognition und Neophobie bei Raben. Charadrius 37 , 127-134.

Fritz, J. & Kotrschal, K. 1999. Social learning in common ravens, Corvus corax. Animal Behaviour 57 , 785-793.

Fritz, J. & Kotrschal, K. 1999. Social constraints and profitability of scrounging affect social learning. In: Dautenhahn, K., Nehaniv, C. (eds.): Proceedings of the AISB`99 symposium on imitation in animals and  artefacts, 6 th -9 th April, Edinburgh : The Society for the Study of Artificial Intelligence and Simulation of Behaviour, 20-26.

Drack, G. & Kotrschal, K. 1995. Aktivitätsmuster und Spiel freilebender Kolkraben Corvus corax im inneren Almtal/Oberösterreich. Monticula 7 , 159-174

Published abstracts

Bugnyar, T. & Heinrich, B. 2003. Hiding in food-caching ravens, Corvus corax. Revista de Ethologia (Supplemento; Contributions to the XXVIII International Ethological Conference, Florianopolis, Br. ) 5 , 57.

Stöwe, M., Bugnyar, T. & Kotrschal, K. 2001. Effects of food quality and food-item size on scrounging in ravens (Corvus corax). Advances in Ethology (Suppl. to Ethology; Contributions to the XXVII International Ethological Conference, Tuebingen, D.) 36 , 270.

Bugnyar, T. & Kotrschal, K. 2001. Do ravens manipulate the others' attention in order to prevent or achieve social learning opportunities? Advances in Ethology (Suppl. to Ethology; Contributions to the XXVII International Ethological Conference, Tuebingen, D) 36 , 106.

Fritz, J., Bugnyar, T., & Kotrschal, K. 1997. Learning or scrounging? Implications of an experimental study with ravens (Corvus corax). Advances in Ethology (Suppl. to Ethology; Contributions to the XXV International Ethological Conference, Vienna, A) 32 , 128.

Bugnyar, T. & Kotrschal, K. 1997. An experimental analysis of social foraging in ravens: individual strategies, scrounging, and deception. Advances in Ethology (Suppl. to Ethology; Contributions to the XXV International Ethological Conference, Vienna, A) 32 , 497.

Contact: Dr. Thomas Bugnyar (email: thomas.bugnyar@univie.ac.at)